DYNAMIC MOTIONS OF THE ALPHA SUBUNIT OF HETEROTRIMERIC G PROTEINS IN THE NUCLEOTIDE- AND RIC-8A-BOUND STATES

The conformational changes and segmental dynamics involved in the G alpha-subunit of heterotrimeric G proteins have been investigated for 3 separate binding states by using binning-time-dependent single-molecule F÷rster resonance energy transfer (smFRET) of freely diffusing proteins and time-resolved fluorescence anisotropy. The bound states include Ric-8A (Resistance to Inhibitors of Cholinesterase-8A (Miller, Emerson et al. 2000; Miller and Rand 2000; Tall, Krumins et al. 2003)), a guanine nucleotide exchange factor (GEF), and nucleotides GDP and GTP. To analyze the smFRET data, energy transfer efficiency histograms were constructed at binning times varied from 1000 to 2,500 ╡s. Then the conformational equilibria and rates of conformational change between end states (GTP-bound, GDP-bound, and Ric-8A-bound) were extracted using the 3-Gaussian model, developed by Gopich and Szabo (Gopich and Szabo 2007; Gopich and Szabo 2010). Using this model, we determined that intra- and inter-domain dynamics occur on the ms time scale. The Helical-Helical conformational changes are relatively small (\u3c 5 ┼), without observable influence from the binding partner (nucleotide or GEF). The intra Ras-like domain conformational changes are somewhat larger (\u3e5 ┼), and have distinct, multiple states regardless of binding partner (GTP, GDP and Ric-8A). The inter-domain conformational changes are much larger (\u3e40 ┼), and likewise exhibit distinct, multiple states that are binding-partner dependent

Scattering for Schr\"{o}dinger operators with potentials concentrated near a subspace

We study the scattering properties of Schr\"{o}dinger operators with bounded potentials concentrated near a subspace of $\mathbb{R}^d$. For such operators, we show the existence of scattering states and characterize their orthogonal complement as a set of surface states, which consists of states that are confined to the subspace (such as pure point states) and states that escape it at a sublinear rate, in a suitable sense. Our proof uses a novel interpretation of the Enss method in order to obtain a dynamical characterisation of the orthogonal complement of the scattering states

Classical Recall: Analysis of the “Mozart Effect” On Basic Mental Tasks

Researchers conducted a study based on the theory of the Mozart Effect to determine how well students at Lindenwood University performed on cognitive tasks when certain variables were manipulated. There were a total of twelve different conditions, in which the order of tasks, music, and hypothesis instructions were varied. It was concluded that no significant difference was found between any of the assigned conditions. Further research needs to be performed to determine if other variables would be better predictors of cognitive achievement, instead of the presence of classical music and priming participants with different hypotheses. If the Mozart Effect is to be researched in the same fashion, perhaps it would be beneficial to vary the type of music

Home Sweet Home

An article published in the Portsmouth Daily Times on September 22, 2020 on the relocation of Indian Head Rock to South Shore Rotary Park.https://scholarworks.moreheadstate.edu/indian_head_rock/1209/thumbnail.jp

Structural and Functional Biomedical Imaging Using Polarization-Based Optical Coherence Tomography

University of Minnesota Ph.D. dissertation. August 2015. Major: Biomedical Engineering. Advisor: Taner Akkin. 1 computer file (PDF); x, 103 pages.Biomedical imaging has had an enormous impact in medicine and research. There are numerous imaging modalities covering a large range of spatial and temporal scales, penetration depths, along with indicators for function and disease. As these imaging technologies mature, the quality of the images they produce increases to resolve finer details with greater contrast at higher speeds which aids in a faster, more accurate diagnosis in the clinic. In this dissertation, polarization-based optical coherence tomography (OCT) systems are used and developed to image biological structure and function with greater speeds, signal-to-noise (SNR) and stability. OCT can image with spatial and temporal resolutions in the micro range. When imaging any sample, feedback is very important to verify the fidelity and desired location on the sample being imaged. To increase frame rates for display as well as data throughput, field-programmable gate arrays (FPGAs) were used with custom algorithms to realize real-time display and streaming output for continuous acquisition of large datasets of swept-source OCT systems. For spectral domain (SD) OCT systems, significant increases in signal-to-noise ratios were achieved from a custom balanced detection (BD) OCT system. The BD system doubled measured signals while reducing common term. For functional imaging, a real-time directed scanner was introduced to visualize the 3D image of a sample to identify regions of interest prior to recording. Elucidating the characteristics of functional OCT signals with the aid of simulations, novel processing methods were also developed to stabilize samples being imaged and identify possible origins of functional signals being measured. Polarization-sensitive OCT was used to image cardiac tissue before and after clearing to identify the regions of vascular perfusion from a coronary artery. The resulting 3D image provides a visualization of the perfusion boundaries for the tissue that would be damaged from a myocardial infarction to possibly identity features that lead to fatal cardiac arrhythmias. 3D functional imaging was used to measure functional retinal activity from a light stimulus. In some cases, single trial responses were possible; measured at the outer segment of the photoreceptor layer. The morphology and time-course of these signals are similar to the intrinsic optical signals reported from phototransduction. Assessing function in the retina could aid in early detection of degenerative diseases of the retina, such as glaucoma and macular degeneration

Directional Ballistic Transport for Partially Periodic Schr\"odinger Operators

We study the transport properties of Schr\"{o}dinger operators on $\mathbb{R}^d$ and $\mathbb{Z}^d$ with potentials that are periodic in some directions and compactly supported in the others. Such systems are known to produce "surface states" that are confined near the support of the potential. We show that, under very mild assumptions, a class of surface states exhibits what we describe as directional ballistic transport, consisting of a strong form of ballistic transport in the periodic directions and its absence in the other directions. Furthermore, on $\mathbb{Z}^2$, we show that a dense set of surface states exhibit directional ballistic transport. In appendices, we generalize Simon's classic result on the absence of ballistic transport for pure point states [36], and prove a folklore theorem on ballistic transport for scattering states. In particular, this final result allows for a proof of ballistic transport for a dense set subset of $\ell^2(\mathbb{Z}^2)$ for periodic strip models.Comment: 42 pages, 1 figur

L1→L∞L^1\rightarrow L^\infty Dispersive estimates for Coulomb waves

We show the time decay of spherically symmetric Coulomb waves in $\R^{3}$ for the case of a repulsive charge. By means of a distorted Fourier transform adapted to $H=-\Delta+q\cdot |x|^{-1}$, with $q>0$, we explicitly compute the kernel of the evolution operator $e^{itH}$. A detailed analysis of the kernel is then used to prove that for large times, $e^{i t H}$ obeys an $L^1 \to L^\infty$ dispersive estimate with the natural decay rate t^{-\f32}.Comment: 60 page

Temperature Trends and Urban Heat Island Intensity Mapping of the Las Vegas Valley

Modified urban climate regions that are warmer than rural areas at night are referred to as Urban Heat Islands or UHI. Islands of warmer air over a city can be 12 degrees Celsius greater than the surrounding cooler air. The exponential growth in Las Vegas for the last two decades provides an opportunity to detect gradual temperature changes influenced by an increasing presence of urban materials. This thesis compares ground based thermometric observations and satellite based remote sensing temperature observations to identify temperature trends and UHI areas caused by urban development. Analysis of temperature trends between 2000 and 2010 at ground weather stations has revealed a general cooling trend in the Las Vegas region. Results show that urban development accompanied by increased vegetation has a cooling effect in arid climates. Analysis of long term temperature trends at McCarran and Nellis weather stations show 2.4 K and 1.2 K rise in temperature over the last 60 years. The ground weather station temperature data is related to the land surface temperature images from the Landsat Thematic Mapper to estimate and evaluate urban heat island intensity for Las Vegas. Results show that spatial and temporal trends of temperature are related to the gradual change in urban landcover. UHI are mainly observed at the airport and in the industrial areas. This research provides useful insight into the temporal behavior of the Las Vegas area

Green Guide to Composites: an environmental profiling system for composite materials and products

Products made from composite materials can offer significant environmental benefits because of their characteristically low weight, good mechanical properties and excellent resistance to corrosion. For example, composites used in cars can reduce the overall weight of the car and so offer fuel savings through the lifetime of the vehicle. However, although the in-service environmental benefits of composites are known, there is far less understanding of the environmental and social implications associated with the manufacture of composite materials and products. Issues affecting the industry include health and safety, the emission of volatile organic compounds (VOCs), energy consumption and toxicity from manufacture. Alternative materials and technologies (such as closed mould processes, natural fibres and low-styrene resins) have been developed to address these problems, but to date there has still been confusion within the industry as to the detailed benefits of these alternatives. This guide has been created to enable the composites sector to understand the environmental and social impacts associated with composite production and assist with the decisions made about material and process choice. The materials and processes modelled are rated from A (good) through to E (poor). Twelve different environmental impacts are individually scored and totalled to give an overall environmental impact summary rating. Two social impact ratings are also given. When measuring environmental impact it is important to consider all the influences through the life of the product. This process is known as Life Cycle Assessment (LCA) and it has been used in this guide for environmental investigation. Because this guide concentrates on materials and manufacturing, as opposed to in-service performance, the impacts associated with products beyond the factory gate (the use, maintenance and disposal stages of the life cycle) have not been assessed. Within the system boundaries for the LCA, three typical product types have been chosen to reflect a range of different components commonly manufactured using composites: • A double curvature panel – this has a surface area of 1m2 with a panel stiffness equivalent to a 4mm thick chopped strand mat laminate. • A flat sandwich panel – measuring 1m x 8m with a 25mm thick core, having a panel bending stiffness equivalent to a sandwich panel with a 4mm thick chopped strand mat skin. • A complex moulded component – with a volume of 770cm3. Similarly, production processes and materials have been selected to provide a balance between systems that are commonly used across the majority of the composites industry and emerging materials with the potential to provide an environmental benefit. For this reason, materials such as hemp fibre and self-reinforced polypropylene have been included in the guide, but materials that are more specific to a single sector (eg aramid fibre) have not been included. Within each specific process there are still many processing variations (eg methods for mixing, curing and trimming) in addition to the material choice possibilities. To enable fair comparisons, a base case has been selected for each process. This is used throughout the guide to allow the merits of each process variation to be assessed